spring mvc json null空转""空串

解决方法和网上的 不太一样 因为SerializerProvider  为StdSerializerProvider的父类，直接从SerializerProvider .setNullValueSerializer（）方法 不允许 所以通过子类StdSerializerProvider调用此方法

applicationContext.xml

    
    <bean  
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
        <property name="messageConverters">  
            <list>  
               <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">  
                   <property name="supportedMediaTypes">  
                       <list>  
                           <value>text/plain;charset=UTF-8</value>  
                           <value>application/json;charset=UTF-8</value>  
                       </list>  
                   </property>  
                   <property name="objectMapper">  
                       <bean class="com.interceptor.ObjectMappingCustomer"></bean>  
                   </property>  
               </bean>     
            </list>  
        </property>  
    </bean>   

ObjectMappingCustomer.java

    package com.interceptor;  
      
    import java.io.IOException;

import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializerProvider;
import org.codehaus.jackson.map.ser.StdSerializerProvider;
      
    public class ObjectMappingCustomer extends ObjectMapper  
    {  
      
        public ObjectMappingCustomer()  
        {  
            super();  
            // 允许单引号  
            this.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);  
            // 字段和值都加引号  
            this.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);  
            // 数字也加引号  
            this.configure(JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS, true);  
            this.configure(JsonGenerator.Feature.QUOTE_NON_NUMERIC_NUMBERS, true); 
            // 空值处理为空串  
            StdSerializerProvider sp = (StdSerializerProvider) this.getSerializerProvider();
            sp.setNullValueSerializer(new JsonSerializer<Object>(){

                @Override
                public void serialize(Object value, JsonGenerator jg,
                        SerializerProvider sp) throws IOException,
                        JsonProcessingException {
                     jg.writeString("");  
                }
                
            });
      
        }  
    }

然后在springmvc  controller里加    @ResponseBody注解就可以了

需要jackson-all.jar

spring mvc json null空转""空串

原文：http://my.oschina.net/angleshuai/blog/385123